Punicalagin: a monomer with anti-Eimeria tenella effect from fruit peel of Punica granatum L

Poultry production was long plagued by coccidiosis, and the development of alternative therapies will make practical sense. In this work, 2 battery experiments were designed. In battery experiment 1, the best effect of 7 anticoccidial herbs (Sophora japonica Linn, Citrus aurantium L, leaf of Acer palmatum, bark of Magnolia officinalis, fruit peel of Punica granatum L., Eclipta prostrata L., and Piper sarmentosum Roxb.) against Eimeria tenella infection of 21-day-old male Chinese Guangxi yellow-feathered chickens were screened out by clinic indexes (bloody feces scores, cecal lesion scores, oocysts output, relative weight gain rate, and survival rate). According to the results from battery experiment 1 and other literature research, we selected 2 monomers which were extracted from fruit peel of Punica granatum L. for further battery experiment 2 which were similar with battery experiment 1. Clinic results showed that Punicalagin had better anticoccidial effect than Ellagic acid. The anticoccidial mechanism exploration results of Elisa, antioxidant test, and pathological observation showed that Punicalagin reduced the cecal inflammation, improved the expression of immunoglobulin in cecal tissue, improved cecal integrity, and restored its REDOX state. Results of 16S rRNA sequencing analysis showed that Punicalagin also maintained the fecal flora health during E. tenella infection through insignificantly increasing the proportion of Lactobacillus and Faecalibacterium as well as significantly reducing the proportion of pathogenic bacteria, Escherichia-Shigella. RNA-Seq analysis results suggested that Punicalagin may play a role in controlling E. tenella infection by interaction with cytochrome P450 family enzymes. Overall, Punicalagin has promising potential as an alternative therapy for chicken Eimeria tenella infection.